Patent US3704445A successfully refreshed from Google Patents.
US3704445A
Expired / Lapsed
US
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Digital read out indicator for vehicles
Assignee: Individual
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Filing: 1971-07-20
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Granted: 1972-11-28
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Expires: 1991-07-20
Abstract
Abstract Apparatus disposed in a vehicle for providing a digital read out indicator for displaying vehicular speed or engine revolutions comprising a mechanical shaft rotated at a speed corresponding to the vehicular speed or engine revolutions, means responsive to the shaft rotation to produce an electrical pulse train at a recurrence frequency proportional to the shaft rotational speed, and digital display means responsive to said pulse train to produce the desired display.
Inventors
- 👤 Richard R Lanham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:00
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/42; G01P3/44; G01P3/48; G01P3/481; G01P3/489; G01P1/00; G01P1/07; G01P1/08; G01P1/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
99 words
In a vehicle having a shaft which turns at a speed designating the revolutions per unit time of the engine or the speed of the vehicle, in combination: first means responsive to the shaft rotation to produce a synchronized electrical pulse train having a variable recurrence frequency equal to the speed of the shaft; a digital display device replacing the vehicle speedometer; and second means including a plurality of decimal counting units coupled between said first means and said device to cause said device to produce a visual digital reading of the exact engine speed or the vehicular speed.
Claim 2
Dependent Claim
99 words
In a vehicle having a shaft which turns at a speed designating the revolutions per unit time of the engine or the speed of the vehicle, in combination: first means responsive to the shaft rotation to produce a synchronized electrical pulse train having a variable recurrence frequency equal to the speed of the shaft; a digital display device replacing the vehicle speedometer; and second means including a plurality of decimal counting units coupled between said first means and said device to cause said device to produce a visual digital reading of the exact engine speed or the vehicular speed.
Claim 3
Dependent Claim
32 words
A vehicle as set forth in claim 1 having an additional combination of first means, second means and device whereby one device displays engine speed and the other device displays vehicular speed.
Claim 4
Dependent Claim
21 words
A vehicle as set forth in claim 1 wherein the second means includes a plurality of decimal indicating thumb limit switches.
Claim 5
Dependent Claim
18 words
A vehicle as set forth in claim 3 wherein the second means includes a limit lamp logic circuitry.
Claim 6
Dependent Claim
61 words
A vehicle as set forth in claim 1, wherein said first means includes means responsive to the shaft rotation to produce an electrical pulse train having a variable recurrence frequency proportional to the speed of the shaft; a clock oscillator and gating circuitry receiving said proportional pulse train and the output from said clock oscillator and producing said synchronized pulse train.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-28 | 1976-05-29 | 1976-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-28 | 1980-05-29 | 1980-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-28 | 1984-05-29 | 1984-11-28 | $7700.00 | Window Closed / Lapsed |